Method of adjusting amplitude of sheds while weaving



March 27, 1962 J. PICANOL 3,026,911

METHOD OF ADJUSTING AMPLITUDE 0F SHEDS WHILE WEAVING Filed. No v. 1,1956 5 Sheets-Sheet 1 PIP miJWJL Arm/Mex:

.1. PICANOL March 27, 1962 METHOD OF ADJUSTING AMPLITUDE OF SHEDS WHILEWEAVING 3 Sheets-Sheet 2 Filed. Nov. 1, 1956 J P lcanol p54? M WATTQQNE' J. PICANOL March 27, 1962 METHOD OF ADJUSTING AMPLITUDE OFSHEDS WHILE WEAVING Filed Nov. 1, 1956 3 Sheets-Sheet 3 INVENTOR JA'lMEPICANOL ATTORNEYS ilnited States Patent O.

METHOD OF ADJUSTING AMPLITUDE OF I SHEDS WHILE WEAVING .laime Picanol,Casa Pairal Catalunya, Zandberg,

Zillebeii-lez-Ypres, Belgium Filed Nov. 1, 1956, Ser. No. 619,786 Claimspriority, application Belgium Dec. 17, 1955 1 Claim. (Cl. 139-79) Inweaving looms substantial advantages may be gained as well known byusing such heddle frame driving mechanisms as will permit adjustment ofthe height of the shed even while the loom is in operation.

The known mechanisms for this purpose are fundamentally arranged so asto permit the adjustment of the movement of all heddle framessimultaneously. Said adjustment is essentially intended for reducing therisk of thread breaks, in order to reduce the length of time duringwhich the loom is inoperative. Consequently, said known mechanisms areused exclusively to enhance the quantitative efficiency of the loom. Infact, as is well known, the risk of thread rupture may be reduced bymaking the shed as small as possible. However, for certain products andparticularly those in which the threads are subject to very hightension, one has to increase the height of the shed, lest the passing ofthe shuttle be unduly impeded as a consequence of the braking action ofthe warp threads.

The present invention relates to a process whereby not only thequantitative, but also the qualitative efficiency is contemplated. Thisaspect is of considerable importance inasmuch, as is well known, anybreaking of threads is liable to leave traces in the fabric. The novelprocess has basically resulted from the fact, as has been established byapplicant, that it is desirable and for the production of certainarticles highly attractive, to be able to impart unequal amplitudes tothe heddle frames, or to groups of heddle frames in one and the sameloom. Tests made in this connection have proved that the grain or theappearance of the fabric may considerably be improved by judiciouslychoosing a different amplitude for the movement of each heddle frame orgroup of heddle frames, it being also possible thereby to furtherincrease the working efficiency by reducing to the bare minimum thenumber of thread breaking cases and consequently the times of untimelyor unforeseen stoppage of the loom.

The invention therefore provides a novel weaving method essentiallycharacterized in that some of the heddle frames move with differentamplitudes as compared with other heddle frames within the same loom.For this purpose use may be made of certain known heddle frame drivingmeans, eg such as are disclosed in the US. Patent No. 2,681,078 of theapplicant, however, using, according to the present invention, a numberof mechanisms such as described therein, in accordance with the numberof heddle frames or groups of heddle frames requiring individualadjustment of their motion amplitude, i.e. independently of the otherheddle frames or groups of heddle frames.

The invention also contemplates the mechanical means, or groups orcombinations of such means, applied or at least liable to be applied inone and the same loom, with a view to putting into effect the processaccording to the invention.

One mode of application will, by way of an example, be describedhereinafter with reference to the accompanying drawings, it beingevident that within the scope of the invention many other combinationsmay be resorted to.

FIGURE 1 is a dia'grammatical side elevational View of a loom showingthe principal elements thereof such 3&2 6,91 l Patented Mar. 27, 1962 2as will permit to locatethe mechanism whereby the novel weaving processaccording to the invention may be put into effect;

FIGURES 2 and 3 are diagrams for the purpose of illustrating the way inwhich two dilferent sheds may be realised in one loom;

FIGURE 4 is a perspective view showing the principal and characteristicparts of duplicate heddle frame driving means, permitting theapplication of the method according to the invention;

FIGURES 5 and 6 are diagrams showing different heddle frames havingdiiierent amplitudes.

In order to put the method of the invention into effect, it sufiicies"to provide for any such means as will be capable of changing theamplitude of angular motion of the rocking levers which impart to theheddle frames the reciprocatingmovement required for producing the shed.Thus, each of the heddle frames may be associated with its ownindependent and individually adjustable driving mechanism, or saidheddle frames may be grouped, each group of heddle frames required toproduce equal heights of shed being provided with a common drivingmechanism.

The diagrams of FIGURES 2 and 3 are schematic representations of amechanism of utter simplicity, whereby it is rendered possible to use,as before, a common cam shaft for all of the driving levers, and yet topermit the latter to produce different amplitudes of the reciprocatingmovements of their respective heddle frames. For this purpose thedriving mechanism has been so arranged as to permit such relativemovement of each of the levers with respect to its cam disc, as willshift the tangent point, i.e. the application point of the heddle framedriving forces. By so shifting the point of application of the drivingforce exerted by said cam disc on said lever, the distance between saidapplication point and the pivoting centre of the lever is modified andconsequently the length of the are through which the end of said levermoves is also changed.

Considering the lever 1 in FIGURE 3 which is pivoted at 2 and connectedat 3 to one of the heddle frames, if said lever is permanently held incontact with the driving cam 4 which rotates about its axis 5, saidrotating cam will cause point 3 to be deflected through the height H,whereby the reciprocating amplitude of the heddle frame is also equal toH. The resulting shed height is also equal to H (see FIGURE 2).Therefore, in this case, said height of the shed depends on the distancebetween the pivot point 2 of the lever 2, and the tangent point of saidlever on said driving cam 4. Said lever is hinged at 2, to the end of acrank 6. It suffices to rotate said crank through a certain angle or soas to cause the lever 1 to shift lengthwise with respect to the cam disc4, in order to increase the distance d, which now becomes D. The levermay for instance be shifted to the position indicated by 1. In thisposition, the lever 1' is hinged at 2' and its end 3' has drawn nearerto the tangent point of said lever 1' on said cam disc 4. For an equalrotation of said cam disc, as in the previous case, the end 3 of saidlever 1' is now deflected through a height h (FIGURE 3), whichcorresponds to a smaller shed, which may also be given as h (FIG- URE2).

Thus, by the simple process of changing the relative position of theheddle frame driving levers with respect to their respective drivingcams, it will be possible, without changing said cams or their movement,to change or to adjust the shed of the different heddle frames in oneand the same loom each in a different way, for a given Weavingoperation.

It will be understood that many other means or mechanisms may be adaptedfor the application of the process according to the invention. 1

FIGURE 4 shows an embodiment of the cranks such as 6, each of which isindependently rotatable around a common axis 7 and is controlled bymeans of a rod 8 adequately supported as at 9 and at its end providedwith a control knob 10. The other parts of the mechanism are such asknown, e.g. from the US. Patent No. 2,681,078 of the applicant.

In the example shown in FIGURE 4 the levers are divided in two groups,each group being individually controlled by one of the cranks 6;obviously more than two cranks may be provided without any difliculty.

FIGURES 5 and 6 are diagrams illustrating the use of cams b foroperating different levers a, so that different heddle frames d may beoperated with different amplitudes. The angular displacements of theheddle frames are indicated by a and 6, while the linear displacementsare indicated by h and H.

The invention extends as well to the weaving process, inasmuch in oneloom and for one weaving operation heddle frames are so moved as toproduce different sheds, as to the mechanisms or parts of mechanismsspecially intended for this purpose.

3,02 ,911 p a t I p,

What I claim is:

In a process of producing a plain Woven fabric in which the warp threadsare threaded through a plurality of heddle frames and reciprocatingmotion is imparted to said heddle frames so as to divide for each weftpick the sheet of warp threads into'upper and lower warp threads formingthe shed through which the shuttle is made to pass, said heddle framesbeing divided into groups of adjacent frames, the step of changing theamplitude of reciprocation of a group of heddle frames without changingthe amplitude of the rest of the heddle frames.

References Cited in the file of this patent UNITED STATES PATENTS2,073,227 Shearer Mar. 9, 1937 2,187,814 Brown Jan. 23, 1940 2,355,531Holmes Aug. 8, 1944 2,355,532 Holmes Aug. 8, 1944 2,356,713 Tuten Aug.22, 1944 2,437,349 Cobb Mar. 9, 1948 2,477,248 Harding July 26, 19492,477,249 Harding July 26, 1949 2,681,078 Picanol June 15, 1954

